Modeling recurring events in a data store

ABSTRACT

Time-related properties may be modeled independent of a base object. Rather than storing time properties with the object, they may be stored independently. A given object may be stored once, even if it has a recurrent time property. The description of a “meeting,” for example, may be stored once. Each occurrence of that object over time may be stored in a “timeslot” (object &lt;foo&gt; occurs at time ‘t’ on day ‘d’). If it is a recurring property, recurrence information may be stored independently. “Exception” information may be stored independently as well.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation and claims benefit to U.S. patentapplication Ser. No. 11/319,905 filed Dec. 28, 2005.

BACKGROUND

In a data storage system, many of the objects stored may be related totime. Examples of data storage systems include message data storagesystems, such as Microsoft Exchange, for example, databases, such as SQLServer, for example, and the like. Events such as meetings,appointments, and tasks, for example, have a very clear timerelationship. Even less obvious events, such as movies, baseball games,and the Tour de France, for example, can have time relationships. Anobject such as a message may have several time relationships (e.g., timesent, time received, time forwarded, time read, etc.). Modeling simpletime relationships, such as time sent, for example, may be simple. Allthat may be needed is to add a property of type “time” to the object.

The problem, however, gets much more complicated when the relationshipbetween the object and time is not 1-to-1 (a single time at which ameeting occurs, or a single time at which a message was received) butrather 1-to-many. Examples of such relationships are “recurring” events,such as a meeting that repeats every week, or a task that must beperformed quarterly. It is not beyond the realm of possibility thateventually a message store may even need to track all the differenttimes a message was read (for example, for regulatory reasons).

In the past, the solution has been to model time-based relationships foreach object type separately. Such a solution, however, makes the task ofproviding a unified view of time-related objects (such as a calendar ofnot only meetings but also other objects) very difficult to implement,support, and extend. For example, it is common for a meeting to repeatevery week, except on holidays. If each time-based relationship weremodeled separately, then an “exception” would need to be added to each,and added consistently with the same rules (what holidays exist? On whatday do they fall? etc.). To resolve these issues, it would be desirableto have a unified scheme to model recurring time relationshipsregardless of the underlying object (e.g., message, meeting,appointment, etc.).

In known systems, there may be grammar for recurrence, but no grammarfor exceptions. An example of an exception might be “the 28^(th)occurrence of this meeting, which usually falls on Monday, should fallon Tuesday.” A typical calendaring program, however, may fail to detectthat the Tuesday on which the 28^(th) occurrence of the meeting is to beheld is a holiday. Typically, such a system is implemented via an object(e.g., calendar entry) with annotations that describe the recurrencerequirements and the exceptions. However, there is typically no way forthe end-user to see the exceptions.

SUMMARY

As disclosed herein, time-related properties may be modeled independentof a base object. Rather than storing time properties with the object,they may be stored independently. A given object may be stored once,even if it has a recurrent time property. The description of a“meeting,” for example, may be stored once. Each occurrence of thatobject over time may be stored in a “timeslot” (e.g., object <foo>occurs at time ‘t’ on day ‘d’). If it is a recurring property,recurrence information may be stored independently. “Exception”information may be stored independently as well.

Thus, a methodology is disclosed for consistent representation ofrecurrence patterns and exceptions on any object. An object-independentmodel may be developed for representing recurring, time-based propertieswith exceptions. A process for developing such an object model, and acomputing system having such an object model developed on it are alsodisclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram depicting example object relationships formodeling recurring events in a message store.

FIG. 2 is a block diagram providing an example scenario whereinrecurring events in a message store are modeled.

FIG. 3 is a block diagram showing an example computing environment inwhich aspects of the invention may be implemented.

DETAILED DESCRIPTION

FIG. 1 is a block diagram depicting example object relationships formodeling recurring events in a message store. As shown, a task, meeting,or other item may be represented by an object 100. The object 100 mayhave an ItemID 102, which is a unique identifier associated with theobject 100. Time and scope information may exist in a Timeslot table110. A timeslot 110 may be defined by a TimeSlot ID 112, an ObjectID113, an item Type 114, and related event scope information such as astart time 115 and an end time 116. A Recurrence may be defined in aRecurrence table 120 by a Timeslot ID 122 and any recurrence information124. An Exception 130 may be an additional Item entry 100 that is linkedby an Exception table 130 using a MasterID 132 and an ExceptionID 134.

If sub-items are allowed, such as sub-tasks, then a Parent-ChildRelationship table 140 may link them together. The table 140 links theparent object 142 to one or more child objects 144. “pk” is a typicalshorthand for “primary key,” which is a unique identifier for an objectin a data store. “fk” is a typical shorthand for “foreign key,” which isa reference to a unique identifier in the data store.

Using this model, an application can quickly build a unified calendar,or similar time-relationship application, using timeslot and object—thetime, object, and relationship are recorded. The recurrence andexception information are more “rationale”—why timeslot contains thedata it does—and so that any changes to the object or relationship canbe made with full knowledge of the reasons behind the relationships thatwere created. For example, if a meeting is rescheduled from everyThursday to every Monday, it is possible that exceptions may be added(for example, an occurrence of the meeting may now fall on Labor Day),or removed (it now avoids Thanksgiving Day).

Thus, such a model may include three concepts that are independent ofthe object itself: a time slot, which may be defined by a start time andend time pair, a recurrence pattern, which indicates how often the itemis to occur, and an exception relationship, which identifies twodiscrete objects that are identical except for the exception.Consequently, an object does not have to know anything about time,recurrence, or exceptions. Any object could be turned into a recurringobject without changing the object itself.

FIG. 2 is a block diagram providing an example of modeling recurringevents in a message store. As shown, a meeting object 202 may be createdto indicate that a meeting is to be held at a particular location, andthat certain attendees are to be invited. The object 202 may be assigneda unique ItemID (e.g., 5). A timeslot table 204 may be created toindicate the start and end times for the meeting. To tie the timeslot tothe meeting defined by the object 202, the timeslot table may refer tothe ItemID of the object 202 (e.g., 5). The timeslot table 204 may alsohave a unique TimeslotID (e.g., 7) assigned to it. At this point (i.e.,without recurrence or exceptions), a calendar entry for each attendeecould be entered once, for a meeting, at the location, beginning at thestart time, and ending at the end time.

Suppose now that the meeting is to recur every Thursday, at thelocation, beginning at the start time, and ending at the end time. ARecurrence table 206 can be created with recurrence information thatindicates that the meeting is to recur accordingly. The Recurrence table206 may refer to the Timeslot ID of the Timeslot table 204. At thispoint (i.e., without exceptions), a calendar entry for each attendeecould be entered for a meeting, at the location, beginning at the starttime, and ending at the end time, every Thursday.

Suppose now that an exception to the recurrence exists on a holiday thatfalls on a Thursday. An Exception table 208 can be created to indicatethat an exception to the recurring condition exists. The Exception table208 may include an Exception table ID (e.g., 19) that uniquelyidentifies the Exception table 208, a Master ID (e.g., 5) thatidentifies the object to which the exception is taken (e.g., meetingevery Thursday), and an Exception ID (e.g., 9) that identifies theobject with which the object associated with the Master ID has anexception relationship.

A Timeslot object 210 can be created to identify, by start and end time,the time slot during which the excepted meeting would have occurred, butfor the exception. The Timeslot object 210 may refer to the ObjectId ofthe exception 208.

An excepted meeting object 212 may be created to define the exceptedmeeting. The meeting object 212 may have a unique Item ID (e.g., 9). Themeeting object 212 may be identical to the meeting object 202, or it maydiffer. For example, the excepted meeting 212 may be held at the samelocation, and include the same attendees, as the usual recurring meeting202. On the other hand, the excepted meeting might occur at a differentlocation and/or include different attendees.

A Timeslot object 214 can be created to identify, by start and end time,the time slot during which the excepted meeting is to occur. TheTimeslot object 214 may refer to the ObjectId (e.g., 9) of the exceptedmeeting object 212. The start and end times defined by the Timeslotobject 214 may be the same as the start and end times defined by theTimeslot object 204 (if, for example, meetings held on holidays are heldat the same time, but in a different location (e.g., in a local barrather than in a company conference room)). On the other hand, the startand end times might differ from those defined by the Timeslot object 204(if, for example, the excepted meeting is to be rescheduled to thepreceding Wednesday).

If the exception itself is recurrent (e.g., meetings are typically heldon Mondays are held on Tuesdays in the summer months; the CEO is anattendee only during the first quarter; meetings that are typically heldin a small, shabby conference room are held in the Board room during thefirst quarter because the CEO is an attendee), a Recurrence object 216can be set up to cause the exception to recur accordingly. TheRecurrence object 216 may refer to the timeslot object 214 that defineswhen the excepted meeting is to occur.

Example Computing Environment

FIG. 3 and the following discussion are intended to provide a briefgeneral description of a suitable computing environment in which anexample embodiment of the invention may be implemented. It should beunderstood, however, that handheld, portable, and other computingdevices of all kinds are contemplated for use in connection with thepresent invention. While a general purpose computer is described below,this is but one example. The present invention also may be operable on athin client having network server interoperability and interaction.Thus, an example embodiment of the invention may be implemented in anenvironment of networked hosted services in which very little or minimalclient resources are implicated, e.g., a networked environment in whichthe client device serves merely as a browser or interface to the WorldWide Web.

Although not required, the invention can be implemented via anapplication programming interface (API), for use by a developer ortester, and/or included within the network browsing software which willbe described in the general context of computer-executable instructions,such as program modules, being executed by one or more computers (e.g.,client workstations, servers, or other devices). Generally, programmodules include routines, programs, objects, components, data structuresand the like that perform particular tasks or implement particularabstract data types. Typically, the functionality of the program modulesmay be combined or distributed as desired in various embodiments.Moreover, those skilled in the art will appreciate that the inventionmay be practiced with other computer system configurations. Other wellknown computing systems, environments, and/or configurations that may besuitable for use with the invention include, but are not limited to,personal computers (PCs), automated teller machines, server computers,hand-held or laptop devices, multi-processor systems,microprocessor-based systems, programmable consumer electronics, networkPCs, minicomputers, mainframe computers, and the like. An embodiment ofthe invention may also be practiced in distributed computingenvironments where tasks are performed by remote processing devices thatare linked through a communications network or other data transmissionmedium. In a distributed computing environment, program modules may belocated in both local and remote computer storage media including memorystorage devices.

FIG. 3 thus illustrates an example of a suitable computing systemenvironment 100 in which the invention may be implemented, although asmade clear above, the computing system environment 100 is only oneexample of a suitable computing environment and is not intended tosuggest any limitation as to the scope of use or functionality of theinvention. Neither should the computing environment 100 be interpretedas having any dependency or requirement relating to any one orcombination of components illustrated in the exemplary operatingenvironment 100.

With reference to FIG. 3, an example system for implementing theinvention includes a general purpose computing device in the form of acomputer 110. Components of computer 110 may include, but arc notlimited to, a processing unit 120, a system memory 130, and a system bus121 that couples various system components including the system memoryto the processing unit 120. The system bus 121 may be any of severaltypes of bus structures including a memory bus or memory controller, aperipheral bus, and a local bus using any of a variety of busarchitectures. By way of example, and not limitation, such architecturesinclude Industry Standard Architecture (ISA) bus, Micro ChannelArchitecture (MCA) bus, Enhanced ISA (EISA) bus, Video ElectronicsStandards Association (VESA) local bus, and Peripheral ComponentInterconnect (PCI) bus (also known as Mezzanine bus).

Computer 110 typically includes a variety of computer readable media.Computer readable media can be any available media that can be accessedby computer 110 and includes both volatile and nonvolatile, removableand non-removable media. By way of example, and not limitation, computerreadable media may comprise computer storage media and communicationmedia. Computer storage media includes both volatile and nonvolatile,removable and non-removable media implemented in any method ortechnology for storage of information such as computer readableinstructions, data structures, program modules or other data. Computerstorage media includes, but is not limited to, random access memory(RAM), read-only memory (ROM), Electrically-Erasable ProgrammableRead-Only Memory (EEPROM), flash memory or other memory technology,compact disc read-only memory (CDROM), digital versatile disks (DVD) orother optical disk storage, magnetic cassettes, magnetic tape, magneticdisk storage or other magnetic storage devices, or any other mediumwhich can be used to store the desired information and which can beaccessed by computer 110. Communication media typically embodiescomputer readable instructions, data structures, program modules orother data in a modulated data signal such as a carrier wave or othertransport mechanism and includes any information delivery media. Theterm “modulated data signal” means a signal that has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. By way of example, and not limitation, communicationmedia includes wired media such as a wired network or direct-wiredconnection, and wireless media such as acoustic, radio frequency (RF),infrared, and other wireless media. Combinations of any of the aboveshould also be included within the scope of computer readable media.

The system memory 130 includes computer storage media in the form ofvolatile and/or nonvolatile memory such as ROM 131 and RAM 132. A basicinput/output system 133 (BIOS), containing the basic routines that helpto transfer information between elements within computer 110, such asduring start-up, is typically stored in ROM 131. RAM 132 typicallycontains data and/or program modules that are immediately accessible toand/or presently being operated on by processing unit 120. By way ofexample, and not limitation, FIG. 3 illustrates operating system 134,application programs 135, other program modules 136, and program data137. RAM 132 may contain other data and/or program modules.

The computer 110 may also include other removable/non-removable,volatile/nonvolatile computer storage media. By way of example only,FIG. 3 illustrates a hard disk drive 141 that reads from or writes tonon-removable, nonvolatile magnetic media, a magnetic disk drive 151that reads from or writes to a removable, nonvolatile magnetic disk 152,and an optical disk drive 155 that reads from or writes to a removable,nonvolatile optical disk 156, such as a CD ROM or other optical media.Other removable/non-removable, volatile/nonvolatile computer storagemedia that can be used in the example operating environment include, butare not limited to, magnetic tape cassettes, flash memory cards, digitalversatile disks, digital video tape, solid state RAM, solid state ROM,and the like. The hard disk drive 141 is typically connected to thesystem bus 121 through a non-removable memory interface such asinterface 140, and magnetic disk drive 151 and optical disk drive 155are typically connected to the system bus 121 by a removable memoryinterface, such as interface 150.

The drives and their associated computer storage media discussed aboveand illustrated in FIG. 3 provide storage of computer readableinstructions, data structures, program modules and other data for thecomputer 110. In FIG. 3, for example, hard disk drive 141 is illustratedas storing operating system 144, application programs 145, other programmodules 146, and program data 147. Note that these components can eitherbe the same as or different from operating system 134, applicationprograms 135, other program modules 136, and program data 137. Operatingsystem 144, application programs 145, other program modules 146, andprogram data 147 arc given different numbers here to illustrate that, ata minimum, they arc different copies. A user may enter commands andinformation into the computer 110 through input devices such as akeyboard 162 and pointing device 161, commonly referred to as a mouse,trackball or touch pad. Other input devices (not shown) may include amicrophone, joystick, game pad, satellite dish, scanner, or the like.These and other input devices are often connected to the processing unit120 a-f through a user input interface 160 that is coupled to the systembus 121, but may be connected by other interface and bus structures,such as a parallel port, game port or a universal serial bus (USB).

A monitor 191 or other type of display device is also connected to thesystem bus 121 via an interface, such as a video interface 190. Inaddition to monitor 191, computers may also include other peripheraloutput devices such as speakers 197 and printer 196, which may beconnected through an output peripheral interface 195.

The computer 110 may operate in a networked environment using logicalconnections to one or more remote computers, such as a remote computer180. The remote computer 180 may be a personal computer, a server, arouter, a network PC, a peer device or other common network node, andtypically includes many or all of the elements described above relativeto the computer 110, although only a memory storage device 181 has beenillustrated in FIG. 3. The logical connections depicted in FIG. 3include a local area network (LAN) 171 and a wide area network (WAN)173, but may also include other networks. Such networking environmentsare commonplace in offices, enterprise-wide computer networks, intranetsand the Internet.

When used in a LAN networking environment, the computer 110 is connectedto the LAN 171 through a network interface or adapter 170. When used ina WAN networking environment, the computer 110 typically includes amodem 172 or other means for establishing communications over the WAN173, such as the Internet. The modem 172, which may be internal orexternal, may be connected to the system bus 121 via the user inputinterface 160, or other appropriate mechanism. In a networkedenvironment, program modules depicted relative to the computer 110, orportions thereof, may be stored in the remote memory storage device. Byway of example, and not limitation, FIG. 3 illustrates remoteapplication programs 185 as residing on memory device 181. It will beappreciated that the network connections shown are exemplary and othermeans of establishing a communications link between the computers may beused.

One of ordinary skill in the art can appreciate that a computer 110 orother client devices can be deployed as part of a computer network. Inthis regard, the present invention pertains to any computer systemhaving any number of memory or storage units, and any number ofapplications and processes occurring across any number of storage unitsor volumes. An embodiment of the present invention may apply to anenvironment with server computers and client computers deployed in anetwork environment, having remote or local storage. The presentinvention may also apply to a standalone computing device, havingprogramming language functionality, interpretation and executioncapabilities.

1. A thin client computing system for generating object-independentrecurring events in a data store, the system comprising: a processor; acomputer-readable storage medium comprising computer executableinstructions, the computer executable instructions, when executed by theprocessor, case the computing system to: defining information indicatinga first object associated with a time-related item sending to a serverthe information defining the first object associated with thetime-related item, the server to store the first object in a data store;defining information indicating a first timeslot object that indicates astart time and an end time associated with the time-related item;sending to the server the information defining the first timeslot objectassociated with the time-related item, the server to store the firsttimeslot object in the data store independent of the first object;defining information indicating a recurrence object that indicates thatthe time-related item is associated with a recurring event; and sendingto the server the information defining the recurrence object associatedwith the recurring event, the server to store the recurrence object inthe data store independent of the first object and the first timeslotobject.
 2. The thin client computing system of claim 1, furthercomprising: defining information indicating an exception object thatindicates that an exception exists to the recurring event; and sendingto the server the information defining the exception object, the serverto store the recurrence object in the data store.